1. Field
This application relates generally to multi-carrier wireless communications, and more particularly to searching for and detecting pilot signals.
2. Background
Wireless communication systems are widely deployed to provide various types of communication (e.g., voice, data, video, etc.) to multiple users. Such systems may be based on code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), or other multiple access techniques.
Multi-carrier communication systems employ multiple carriers for data transmission to a single end-point. A pilot is often transmitted from a transmitter (e.g., a base station) to a receiver (e.g., a terminal) to assist the receiver in performing various functions such as, for example, channel estimation, timing and frequency acquisition, data demodulation, received signal strength measurements, etc.
A terminal may hand-off from one base station to another. To facilitate such handoffs, the terminal periodically searches for base stations on alternate frequencies. If a terminal detects a base station which may be a candidate for handoff, it may be added to the terminals active set of base stations. The detected frequency may be one of multiple frequencies supported by the base station. However, if the terminal did not initially detect the additional frequencies, the terminal may be unable to later use those frequencies. It would be desirable to have a method of searching for and detecting multiple pilot frequencies supported by a particular base station.